Tricorythodes faeculopsis, Belmont, Enide Luciana L., Salles, Frederico F. & Hamada, Neusa, 2011

Belmont, Enide Luciana L., Salles, Frederico F. & Hamada, Neusa, 2011, Three new species of Leptohyphidae (Insecta: Ephemeroptera) from Central Amazon, Brazil, Zootaxa 3047, pp. 43-53 : 44-47

Tricorythodes faeculopsis sp. nov.

( Figs. 1–9 )

Diagnosis. This species can be distinguished from other species of the genus by following combination of characteristics: nymph - 1) maxillary palp 1-segmented, elongate, 2× longer than wide, with a short terminal seta; 2) legs light yellow without conspicuous marks; 3) tarsal claws with 4–6 marginal and 1 pair of submarginal denticles, and with apical seta; 4) abdomen pigmented gray with two white marks on each tergite, forming two whitish longitudinal lines. Subimago - 1) abdomen yellowish with whitish longitudinal mark; 2) penes long and conical, with sclerotized lateral margins.

Description. Nymph. Length: Body, 0.7–3.6 mm; Mesonotum, 0.4–1.6 mm; Caudal filaments, 0.9–1.8 mm. General coloration yellowish with gray marks ( Fig. 1 ). Body elongate, base of abdomen slightly wider than apex. Head: yellowish with gray marks between ocelli. Genal and frontal projection absents; tubercles absent; eyes of males not divided; mouthparts yellowish; labrum with a deep anteromedian emargination ( Fig. 2 ); maxilla with simple setae and pectinate setae ( Fig. 4 ); maxillary palp 1-segmented, elongated, 2× longer than wide, with short, terminal seta ( Fig. 4 ); glossa not fusioned, with flattened setae laterally fringed and paraglossa with bipectinate and fringed flattened setae ( Fig. 3 ). Thorax: Coloration light yellow with gray marks. Tubercle absent on pronotum and mesonotum. Anterolateral corner of pronotum not projected. Hind wing pads absent. Legs light yellow without conspicuous marks; ratio of foreleg 1.6:1(0.3):1:1.8; femora narrow (2× longer than wide) ( Fig. 8 a, 8b, 8c); outer margin of femora with long setae; transvers row of setae on anterior surface of femur on median region ( Fig. 8 a); tibiae dorsally with a row of spine-like setae and laterally with hair-like setae; tarsal claws with apical seta, 4–6 marginal and 1 pair of submarginal denticles ( Fig. 7 ). Abdomen: yellowish shaded with gray and with a whitish longitudinal mark. Posterolateral margin expanded on segments III–VII. Operculate gill triangular with ridge at base; coloration yellowish with gray mark at base ( Fig. 6 ); operculate gill reaching segment VII; gill formula 2/3/3/ 3/1. Caudal filaments whitish.

Male subimago. Length: Body, 2.9 mm; Mesonotum, 1.3 mm. General coloration yellowish, with parts of mesonotum light brown. Head: yellowish. Eyes black. Antennae, scape and pedicel yellowish, flagellum hyaline. Thorax: light brown. Mesoscutellum without membranous filaments. Legs light brown with whitish longitudinal mark. Abdomen: yellowish with whitish longitudinal mark. Forceps 3-segmented, long and slender; base of segment II with basal swelling. Penes long and conical, with lateral margins sclerotized ( Fig. 9 ); lobes apically rounded, divided on apical 1/6. Caudal filaments gray translucent.

Life cycle associations. The association between male subimago and nymph was made by rearing the nymph.

Biological aspects. Nymphs were found in roots with sediment in the margins of streams with fast-flowing water. Once to the body of the nymphs is covered with sediment, it is somewhat difficult to find them in the field.

Etymology. “ faeculopsis ”: Latim - faecul = sediment; opsis = appearance (related to habitat), this species was named due to the individual's body completely covered by sediment.

Discussion. Nymphs of Tricorythodes faeculopsis sp. nov. are more similar to those of T. sordidus Allen, 1967 , T. popayanicus Domínguez, 1982 and T. yura Molineri, 2002 . However, T. faeculopsis sp. nov. can easily be separated from these possibly related species (and all other of the genus) by abdominal pigmentation, tarsal claws denticulation and maxillary palp segmentation.

Material examined. Holotype: Nymph (in alcohol), Brazil, Amazonas, Manaus, Reserva Florestal Adolpho Ducke, igarapé Tinga (2°56'41.0"S 59°57'22.0"W), iii-2010, Belmont, E.L.L, Linard, V. col. ( INPA); Paratypes: 3 nymphs (in alcohol) and 1 subimago (in slide), Reserva Florestal Adolpho Ducke, igarapé Ipiranga (2°59'36.3"S 59°53'25.5"W), iv-2010, Belmont, E.L.L, Linard, V. and Santos-Neto, C.R. col. ( INPA); 4 nymphs (in alcohol) same data (CEUNES).

Figures

FIGURES 1 – 5. Tricorythodes faeculopsis sp. nov. 1. nymph; 2. labrum; 3. labium (left dorsal view and right ventral view); 4. right maxilla, maxilary palp in detail; 5 a. left mandible (d. v.); 5 b. right mandible (d. v.). (AMR—anteromedian region; Gglossa; PG—paraglossa; LP—labial palp; DS—dentisetae; MP—maxilary palp; In—incisors; MR—molar region).

FIGURES 6 – 9. Tricorythodes faeculopsis sp. nov. 6. right operculate gills (d. v.); 7. anterior tarsal claw; 8 a. foreleg; 8 b. midleg; 8 c. hind leg; 9. genitalia (male subimago). (MD—marginal denticles; SD—submarginal denticles; HS—hairlike setae; F—forceps; SP—styliger plate).